Method and apparatus for eliminating smoke emissions from incinerators

ABSTRACT

Smoke emissions are eliminated from an incinerator by admitting cool air into a stack arranged to receive smoke from a combustion chamber for inducing a draft in the stack which opposes a natural draft therein. Smoke is carried along by the induced draft and returned to the combustion chamber, so that only gases free of particulate matter are emitted from the stack. The induced draft returning to the combustion chamber as overfire air has sufficient pressure for creating turbulence in the combustion chamber for retaining the smoke in the combustion chamber a time sufficient to ensure complete combustion thereof. The cool air is admitted into the stack by a louvered portion provided in the stack and arranged adjacent the combustion chamber, and, alternatively, one or more louvered elements connected to the combustion chamber and the stack so as to be in parallel with the louvered portion. Ducts are connected to the louvered portion and louvered elements to return smoke to the combustion chamber.

United States Patent [191 Wilson [451 Dec. 4, 1973 METHOD AND APPARATUSFOR ELIMINATING SMOKE EMISSIONS FROM INCINERATORS Wallace C. Wilson,1314 E. Viola Ave., Yakima, Wash. 98901 22 Filed: Feb. 28, 1972 211Appl. No.: 229,659

[76] Inventor:

Primary Examiner-Kenneth W. Sprague Attorney-Harvey B. Jacobson [5 7ABSTRACT Smoke emissions are eliminated from an incinerator by admittingcool air intoa stack arranged to receive smoke from a combustion chamberfor inducing a draft in the stack which opposes a natural draft therein.Smoke is carried along by the induced draft and returned to thecombustion chamber, so that only gases free of particulate matter areemitted from the stack. The induced draft returning to the combustionchamber as overfire air has sufiicient pressure for creating turbulencein the combustion chamber for retaining the smoke in the combustionchamber a time sufiicient to ensure complete combustion thereof. Thecool air is admitted into the stack by a louvered portion provided inthe stack and arranged adjacent the 4 Claims, 3 Drawing Figures METHODAND APPARATUS FOR ELIMINATING SMOKE EMISSIONS FROM INCINERATORS-BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates generally-to apparatus for-eliminating smoke emissions fromincinerators, and, more specifically, to such a apparatus forincinerators primarily intended to burn paper.

2. Description of the Prior' Art Incinerators-have long been used-tobumtrash, and particularly paper, both-for large buildings and individ ualresidences. In recent years, however, the problem of airpollution hasresulted'in the use ofsuchincinerw tors to be either eliminated bylegislation or'effectively eliminated by strict emissioncontrol'stan'dards.

The most objectionable air pollutant normally emitted from anincinerator is smoke. Smoke'is gasbome particles resulting fromincomplete combustio'n'of the materials being burned. It has long beenknown that if these particles, orparticulate matter, can be eitherrecycled to the combustion chamber or further burned in an additionalcombustion chamber, theycan' theoreti+ cally be eventually eliminated bycomplete combustion. In the past, attempts have been made to.recyclethis particulate matter to the combusti'onch'amber by running aduct from the stack to the middle or lower portion of the combustionchamber so as to employ-the draft created in the combustion chamber todraw the particulate matter through the duct'and combustion chamber andback to the stack.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an improved apparatus for eliminating smoke emissions fromincinerators. It is a further object of the present invention to provideapparatus which will retnm' smoke laden air through thecombustion'chamber in the form that only gases free of particulatematter are emitted from the stack. The step of returning'includ'esthesteps of returning the induced draft as overfire air and pro- 1viding sufficient pressure in the induced draft for creating turbulencein the combustion chamber for retaining the smoke in the combustionchamber a time sufficient to ensure complete combustion thereof.

Apparatus for carrying out the method accordingto the present inventionhas a stack arranged to receive smoke and with means for admitting coolair into the stack for inducing a draft thereinwhich opposes a naturaldraft in the stack, and means connected to the stack for returning smokecarried alongby the induced draft so that only gases free of particulatematter areemitted' from the stack. Container means may be provided havofthe present invention to connected tothe container means and arrangedin' communication with the combustion chamber for receiving smoketherefrom.

In apreferred embodiment of'apparatus according to the presentinvention, the means for admitting is a louvered portion formed in thestack and arranged adjacent'the combustion chamber. The means forreturning may include a ductconnected to the container'means andarrangedin communication with the combustion chamber so as to providethe overfire air supply for cre-' ating sufficient turbulence in thecombustion chamber for retaining the smoke in the combustion chamber atime sufficient to ensure complete combustion thereof.

A preferred embodiment of the present invention has at least onelouvered element connected to the container means and arranged incommunication with the combustion chamber for receiving smoke therefrom,

and connected to the stack and in parallel ,with the louvered portion ofthe stack. A duct is connected to the louvered element and to thecontainer means for returning smoke from the louvered element to thecombustion chamber.

These together with other objects and advantages which will becomesubstantially apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1- is a front elevational viewshowing an incinerator'according to the present invention. I

FIG. 2 is a top plan view showing the incinerator of FIG. 1.

FIG. 3 is a sectional view taken generally along the line 3 -3 of FIG;2.

DESCRIPTION OFTHE PREFERRED EMBODIMENTS Referring now to the drawings,FIG. 1 shows an incinerator 10 according to the present invention havinga stack 12 with a pipe portion 13 and means 14 for ad- "mitting' coolair into stack 12 for inducing a draft cess openings 21, 22,respectively. Hinges 26, 28 may be of any suitable, known type, such aspiano hinges.

Bar and keeper assemblies 30, 32 are provided to retain doors 23,124,respectively, in their closed position with respect to access openings21, 22, respectively. Barrel 20 is provided with a vent 34- in door 23,a vent 36 (FIG.- 2) having a pivotally mounted cover member 37, vents 38and 40', and vent 41 in door 24'. Vents 39, 41 are not shown in FIG. 3.Vent 36' is arranged in a top wall"42-( FIG. 2) and vents 38, 40 arearranged in a cylindrical-sidewall'44.Walls 42, 44 are combined with abottom wall 45 (FIG. 3) to define a combustion chamber 46 (FIG. '3 Stack12, by means of being connected to container means 1 8*, is incommunication with combustion chamber 46 by means of opening 47 forreceiving smoke therefrom.

Means 14 has a louvered portion 48 formed in stack 12 and arrangedadjacent combustion chamber 46. Portion 48 is formed by a plurality offins 50 arranged about the periphery of stack 12. Pins 50 are formed ina suitable, known manner, such as by stamping. Means 16 has a'duct 52(FIG. 3) connected to stack 12 and in communication therewith by meansof an opening 54 provided in louvered portion 48, and is connected tocontainer means 18 and arrangedin communication with combustion chamber46 by means of an opening 55 provided in top wall 42. In this manner,the induced draft returning through duct 52 is designed so as to providean overfire air supply for creating sufficient turbulence in combustionchamber 46 for retaining the smoke in combustion chamber 46 a timesufficient to ensure complete combustion thereof. Duct 52 has an elbowportion 56 connecting same to louvered portion 48 at opening 54. Ascreen 57 may be arranged at the outlet of pipe portion 13 to catch anyashes or other particles that may allude. the induced draft in louveredportion 48 and pass up the stack 12.

' Although it is to be understood that an incinerator according to thepresent invention may have only stack 12 with a louvered portion 48, theparticular embodiment shown in the drawings has a pair of louveredelements 58 connected to container means 18 and arranged incommunication with combustion chamber 46 via openings 60 formed in topwall 42 and in communication with stack 12 for receiving smoketherefrom. Elements 58 are also connected to stack 12 for communicationtherewith by means of openings 62. The elements 58 are connected tostack 12 in parallel with lou-' vered portion 48. Fins 50 are alsoformed in pipe portions 63 of elements 58. A duct 64 is connected to arespective louvered element 58 and is in communication therewith bymeans of an opening 66. Ducts 64 are also connected to container means18 and are in communication with combustion chamber 46 by means ofopening 68 provided in wall 44 by returning smoke from louvered element58 to combustion chamber 46. Each open, for cleaning the residue ashfrom combustion chamber 46 of barrel 20. Incinerator is intended toreduce the entire composition of paper 82 into ashes.

louvered element 58 has an elbow 70 and a pipe 72 as In operation,trash, preferably paper 82, is firmly packed and evenly distributed inbarrel 20 by passing same through access opening 21 with door 23 pivotedout of the way (not shown). Paper 82 may be packed into combustionchamber 46 up to barrel ring 84. Vent 36 is left open at all times. Vent34 is preferably left partially open for regulation of the oxygenrequired for combustion. After a fire is started in combustion chamber46, cold air from the atmosphere enters louver portion '48 and louverelements 58 through fins therof. This cold air sets up an induced draftwhich forces hot air and other gases carrying particulate matter intothe return duct 52, 64 and into combustion chamber 46 as overfire air.With proper design, the pressure of the induced draft entering intocombustion chamber 46 provides sufficient overfire pressure for creatingturbulence in combustion chamber 46 for retaining the smoke incombustion chamber 46 a time sufficient to ensure complete combustionthereof. The arrows in FIG. 3 of the drawings show the various flowpaths. Access opening 22 may be used, when door 24 is swung These ashescan be used as, for example, fertilizer which will be beneficial to theenvironment. When properly operated, incinerator 10 will emit smoke, orcarbons, in an amount not to exceed three-quarters of one ringleman avalue taken from a standard Ringleman Chart and then only will it emitsuch an amount for less than 30 seconds. I

The cold air will cause the induced draft due to its tendency to settlewhen mixed with warm air. The foregoing is considered as illustrativeonly of the principles of the invention. Further, since numerousmodifications and changes will readily occur to those skilled in theart, it is not desired to limit the invention to the exact constructionand operation shown and described, and accordingly all suitablemodifications and equivalents may be resorted to, falling within thescope of the invention. What is claimed as new is as follows:

1. An incinerator comprising in combination:

a. a stack arranged to receive smoke, and including means for admittingcool air into the stack for inducing a draft therein which opposes anatural draft in the stack;

. means connected to said stack for returning smoke carried along by theinduced draft, so that only gases free of particulate matter are emittedfrom said stack; and

0. container means having wall defining a combustion chamber, andwherein said stack is connected to said container means and arranged incommunication with the combustion chamber for receiving smoke therefrom,said means for admitting including alouvered portion forrnedin saidstack and arranged adjacent to the combustion chamber, the means forreturning including a duct connected to said container means andarranged in communication with the combustion chamber so as to providean overfire air supply for creating sufficient turbulence in thecombustion chamber for retaining the smoke in the combustion chamberatime sufiicient to ensure complete combustion thereof, and at least onelouvered element connected to said container means and arranged incommunications with the combustion chamber for receiving smoketherefrom, and connected to said stack in parallel with the louveredportion of said stack, a duct connected to said louvered element andsaid container means for returning smoke from said louvered element tothe combustion chamber.

2. An incinerator comprising in combination:

a. a stack arranged to receive smoke, and including means foradmitting'icool air into the stack for inducing a draft therein whichopposes a natural draft in the stack;

b, means connected to said stack for returning smoke carried along bythe induced draft, so thatonly gases free of particulate matter areemitted from said stack; and

c. container means having walls defining a combustion chamber, andwherein said stack is connected to said container means and arranged incommunication with the combustion chamber for receiving smoke therefrom,at least one louvered element connected to said container means andarranged in communication with the combustion chamber for ranged incommunication with the combustion chamher.

4. A structure as defined in claim 1, wherein the means for returningincludes a duct connected to the louvered member, and to said containermeans and arranged in communication with the combustion chamber.

1. An incinerator comprising in combination: a. a stack arranged toreceive smoke, and including means for admitting cool air into the stackfor inducing a draft therein which opposes a natural draft in the stack;b. means connected to said stack for returning smoke carried along bythe induced draft, so that only gases free of particulate matter areemitted from said stack; and c. container means having wall defining acombustion chamber, and wherein said stack is connected to saidcontainer means and arranged in communication with the combustionchamber for receiving smoke therefrom, said means for admittingincluding a louvered portion formed in said stack and arranged adjacentto the combustion chamber, the means for returning including a ductconnected to said container means and arranged in communication with thecombustion chamber so as to provide an overfire air supply for creatingsufficient turbulence in the combustion chamber for retaining the smokein the combustion chamber a time sufficient to ensure completecombustion thereof, and at least one louvered element connected to saidcontainer means and arranged in communications with the combustionchamber for receiving smoke therefrom, and connected to said stack inparallel with the louvered portion of said stack, a duct connected tosaid louvered element and said container means for returning smoke fromsaid louvered element to the combustion chamber.
 2. An incineratorcomprising in combination: a. a stack arranged to receive smoke, andincluding means for admitting cool air into the stack for inducing adraft therein which opposes a natural draft in the stack; b. meansconnected to said stack for returning smoke carried along by the induceddraft, so that only gases free of particulate matter are emitted fromsaid stack; and c. container means having walls defining a combustionchamber, and wherein said stack is connected to said container means andarranged in communication with the combustion chamber for receivingsmoke therefrom, at least one louvered element connected to saidcontainer means and arranged in communication with the combustionchamber for receiving smoke therefrom, and connected to said stack inparallel with the louvered portion of said stack, a duct connected tosaid louvered element and said container means for returning smoke fromsaid louvered element to the combustion chamber.
 3. A structure asdefined in claim 2, wherein the means for returning includes a ductconnected to the louvered member, and to said container means andarranged in communication with the combustion chamber.
 4. A structure asdefined in claim 1, wherein the means for returning includes a ductconnected to the louvered member, and to said container means andarranged in communication with the combustion chamber.